What are the various issues with using geothermal heat pumps in hot climates with sandy soil conditions like we have in central Florida? On one hand, it is my understanding that sandy soils are very poor at heat transfer. On the other hand, our irrigation wells are usually < 50' and the water table is often a few feet from the surface.

From what I read, the huge cost increase over air source HP is the drilling or trenching costs. I would think that those costs would be greatly reduced in central Florida's sandy conditions where you could easily trench in a horizontal line and easily drill down to water.

Are the ground temperatures here low enough to allow a ground sourced heat pump to work efficiently?

Thanks for your thoughts.